drm/etnaviv: add helper to extract bitfields

Add a helper to extract etnaviv bitfields from register values.

Acked-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
1 file changed